The bottom bar is located under the timeline and brings additional buttons and information.
The buttons allow to change the view of the timeline and the behaviour mode of neighbour sheets.
The options on the left are modes that influence how the adjacent sheets behave when you resize a sheet.
The options on the right change the focus with the zoom and position in the timeline.
The informative text under the layers changes according to the situation.
If nothing is selected in the timeline, it will display the length of the shot and the number of sheets.
If you move the current frame, it will display the length of the current sheet and its position.
If one or several sheet(s) are selected, it will display the number of sheet(s) and their range in frame length and position.
If you go to another layer, it will display the length of the layer in number of frames, and the number of sheets contained in the layer.
A timestamp is displayed when you play the animation.